Piston ring



July 10, 1934. w. WUE RFEL I 1,965,623

PISTON RING Filed Feb. 1930 Patented July 10, 1934 UNITED STATES PATENT OFFICE PISTON RING William Wuerfel, Philadelphia, Pa., assignor to Wilkening Manufacturing Company, Philadelphia, Pa., a corporation of Delaware Application February 3,

Claims.

by to decrease the consumption of lubricating oil and to prevent needless fouling of the spark plugs.

One of the objects of the present invention is to provide an improved type of slotted oil ring which will more effectively prevent excess oil passing the ring, while permitting a sufiicient amount to do so, in order to insure the proper lubrication of the cylinder walls and the pistons.

Another object is the provision of an oil ring which is provided with a series of slots extending through the ring from the outer to the inner surfaces which serve to collect oil working along the cylinder walls, said slots communicating with the interior of the piston by means of holes provided in the piston wall at the ring groove thereof.

A further object of my invention is the provision of a slotted oil ring, having its outer periphery composed of two distinct surfaces, to wit, a lower cylindrical surface which bears against the cylinder wall and an upper conical surface which inclines towards said cylindrical surface or tapers away from the cylinder wall at a slight angle and which extends from the upper side face of the ring to the upper edges of the slots, or just above the slots, so that the ring on its upward stroke will tend to ride over the film of oil on the cylinder wall, and on its downward stroke may remove some of the oil from the cylinder wall, partly by the lowermost edge of the ring and partlyby the upper edges of the slots in the ring.

These and other objects are attained by the novel features of construction as hereinafter set forth and illustrated in the accompanying drawing, wherein:

Figure 1 is a section along the line 1-1 of Figure 3, and showing a section of the piston wall with the ring seated in the groove.

Figure 2 is a perspectiveview of the piston ring, v

Figure 3 is a -section along the lines 33 of Figure 4, and c Figure 4 is a-side View of the piston ring.

In Figure 1 of the drawing a fragmentary sectional view of a conventional piston is shown,- including the conventional groove'5, and the series of downwardly inclined radial oil drain holes or apertures 6, intermediate the bottom of the ring groove 5 and the interior of the piston.

1930, SerialNo. 425,639

The ring 7 of the novel construction of the instant invention is of the split, cast-iron type, having the beveled overlapping ends 8 and 9. The manner of splitting the ring is wholly 0ptional however, because it might equally well be a straight out or rabbeted, or the like.

A series of radial slots 10 extend through the ringfrom the outer to the inner periphery thereof, substantially midway of the upper and lower parallel side walls 11 and 14 of the ring. The upper and lower side walls 12 and 13 of the radial slots 10 are parallel to each other and parallel with and more or less equidistant from the upper and lower side walls 11 and 14 respectively of the piston ring. The end walls 1'7 01' the slots 10 are outwardly diverging cylindrical surfaces, the axis of which is parallel with the axis of the piston ring. By reason of the outward divergence of the cylindrical end walls 17 of the slot 10, the maximum length of the slot is presented on the outer periphery of the ring, while the minimum length of the slot is presented on the inner periphery of the ring, as will be seen more particularly in Figure 3.

The upper outer peripheral portion 15 of the ring is conical or beveled at a slight angle, and this conical surface 15 starts substantially at, or slightly above, the outer edge of the upper walls 12 of the slot 10, and extends up to the upper side wall 11 of the ring. The conical surface 15 and the cylindrical surface 19 of the ring 7 and the upper walls 12 of the slot 10 more or less thus intersect or meet each other at about the same annular zone or line 16. This is most clearly shown in Figure 1.

The novel oil ring of the instant invention may be self-expanding, that is, it may have the tension set into it so that it will bear against the cylinder wall in an outward radial direction by reason of its own internal forces, or this oil ring may be used, if desired, in conjunction with an expanded spring of any construction inserted behind the ring and exerting an outward radial pressurethereon.

In the operation of this oil ring, the ring, during the upward stroke, tends to ride over the film of oil adhering to the cylinder wall, by reason of the inclined or beveled conical surface 15, some of which oil however is scraped oil by the lower edges 20 or the slot 10. The oil thus scraped off the cylinder wall by the lower edge 20 passes into the slot 10 and is drained through the drain apertures 6 back into the crankcase. This partial oil removal on the upward stroke allows just enough oil to remain to give proper lubrication.

On the downward stroke both the lower edge 21 is well as the edges 16 of the slots 10 come into lay in acting upon the film of oil on the cylinder wall. The oil affected by the lower edge 21 is scraped directly down the cylinder wall back into the crankcase, while the oil affected by the edges 16 is scraped into the slot 10 and then drained into the crankcase through the drainholes 6.

By this novel combination of scraping edges, the maximum oil is removed back into the crankcase on the downward stroke, while on the upward stroke sufiicient amount of oil is left to permit proper lubrication. By reason of the more or less close relation between the inclined surface 15 and the slots 10, the oil scraping action of this ring, so essential to the prevention of what may be termed oil pumping, is at the same time accompanied by a proper and suiiicient lubrication.

The novel oil ring of the present invention may be used in conjunction with any other suitable rings provided in the other ring grooves of the piston, or, if desired, the oil rings of the present invention may be used in more than one ring groove of the piston.

I am aware that my invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination with a piston having an annular ring-receiving groove and oil draining passageways extending from said ring-receiving groove through the wall of the piston, of a onepiece piston ring having its outer periphery composed of a lower cylindrical portion of a width substantially greater than one-half of the total overall axial width of the ring; and an adjacent, upper, frusto-conical chamfered portion tapered inwardly and upwardly from its cylinder contacting edge, said frusto-conical portion being of an overall axial width substantially less than one-half of the total overall axial width of the ring, a series of elongated slots extending through the cylindrical portion of the outer periphery of the ring and being entirely clear of the conical chamfered portion thereof, said elongated slots extending through said ring in a generally radial direction, being disposed entirelybeneath said conical chamfered portion, and having pairs of spaced, plane, parallel longitudinal walls and having outwardly diverging end walls; the distance between adjacent slots on the outer periphery of the ring being substantially less than the minimum peripheral dimensions of the slots; the lower edge of said frusto-conical chamfered portion forming an oil scraping edge.

'2. A one-piece piston ring adapted for use in combination with a piston having an annular ring-receiving groove, and oil drainage passageways extending from said ring-receiving groove into the interior of the piston, said piston ring having its outer periphery composed of a lower cylindrical portion of a width substantially greater than one-half of the total overall axial width of the ring; and an adjacent, upper, frustro-conical chamfered portion tapered inwardly and upwardly from its cylinder contact edge, said frustro-conical portions being of an overall axial.

width substantially lessthan one-half of the total overall axial 'width of the ring, a series of elongated slots extending through the cylindrical portion of the outer periphery of the ring and being entirely clear of the conical chamfered portion thereof, said elongated slots extending through said ring in a generally radial direction, being disposed entirely beneath said conical chamfered portion, and having pairs of spaced, plane, parallel side walls and having outwardly diverging end walls;--the distance between adjacent slots on the outer periphery of the ring being substantially less than the minimum peripheral dimensions of the slots; the lower 'edge of said frustro-conical chambered portion forming an oil scraping edge.

3. A one-piece piston ring provided with parallel-walled, slot-like oil passages extending therethrough from the outer to the inner periphery, the portion of the outer periphery to one side of said passages being substantially in the form of a cylinder and the portion on the other side being substantially frustro-conical;-the parallel walls of said slot-like oil passages being disposed at substantially a right angle to the axis of the piston ring;an edge of said frustroconical surface of the piston ring coinciding with one of the side-walls of said oil passages, and cylinder-contact portions at the outer periphery of the piston ring intermediate adjacent slot-like oil passages.

4. A one-piece piston ring provided with parallel-walled, slot-like oil passages extending therethrough from the outer to the inner periphery, the portion of the outer periphery to one side of said passages being substantially in the 5 form of a cylinder and the portion on the other side being substantially frustro-conical;-the lower edge of said frustro-conical portion forming a peripheral oil scraping edge substantially coextensive with the periphery of the piston 120 ring;an edge of said frustro-conical surface of the piston ring coinciding with oneof the sidewalls of said oil passages, and cylinder-contact portions at the outer periphery of the piston ring, intermediate adjacent slot-like oil passages. 1 5

5,, A one-piece piston ring provided with parallel-walled, slot-like oil passages extending therethrough from the outer to the inner periphery, the portion of the outer periphery to one side of said passages being substantially in the 130 form of a cylinder and the portion on the other side being substantially frustro-conical;--the parallel walls of said slot-like oil passages being disposed at substantially a right angle to the axis of the piston ring, and the lower edge of 135 said frustro-conical portion forming a peripheral oil scraping edge substantially coextensive with the periphery of the piston ring;an edge of said frustro-conical surface of the piston ring coinciding with one of the side-walls of said oil 140 passages, and cylinder-contact portions at the outer periphery of the piston ring, intermediate adjacent slot-like passages.

WILLIAM WUERFEL. 

